Radiological exposure from a terror event has been identified by the CDC and the Office of Homeland Security as a potential threat worthy of significant national preparedness. Little research has been done, however, to develop risk communication strategies for those with limited literacy. The specific aims of this research are: 1. To test whether tailored communication for those with low literacy increases overall understanding of RTEs as well as eases fear and increases self efficacy compared to existing risk messages, and 2. To assess whether new approaches to designing risk communication - perceptual mapping and physiological testing- are valid methods to develop emergency preparedness materials for people with low literacy. The study will use new approaches to designing risk communication (RC) that involves modeling the target group's conceptualization of a situation, designing message strategies around those conceptual models and testing, under laboratory conditions, the cognitive, emotional, decisional, behavioral and physiological effects of such messages. This will be done using vector mathematical modeling to create perceptual maps that can be used to compare current RC materials to pilot messages designed from the perceptual maps. Reactions to these materials will then be tested using psycho- physiological measures (eye-tracking, pupil dilation, heart rate, respiration rate, skin conductance and body temperature) to assess their effectiveness in reducing fear and increasing willingness to comply with recommended actions. The research will have four phases: 1. Conduct three to four focus groups with subjects (N=30) with lower-literacy (d 6th grade reading level) and create a perceptual mapping instrument on perceptions of a radiation terror event;2. Administer the perceptual mapping survey instrument to subjects (N=50) with low literacy;3. Analyze perceptual mapping data and design an adapted RC aid for people with low literacy using vector message design methods;4. Conduct a pilot study with subjects (adults with d6th grade literacy level;N=50) using psycho-physiological measures to assess the types of messages most likely to reduce uncertainty, decisional conflict, and physiological stress/tension and increase the willingness to comply with recommendations if a radiation event occurred. Pilot subjects will be randomized to review the adapted RC aid (Experimental Group) or an existing CDC decision aid (Control Group). We will test the following hypotheses: 1. Experimental subjects will be more likely than controls to (a) report intent to comply with radiation event recommendations and (b) report less uncertainty and more self efficacy.;2. Experimental subjects will be more likely than controls to have aggregated mental maps in which "self" is positioned farther away from negative cognitive/affective concepts (fear, uncertainty) associated with a radiation event. We predict that communication aids designed using these methods will provide predictive models for how to communicate risk information effectively to low-literacy populations in the event of a public threat with a high perceived degree of risk. The impact of developing and testing these methods to improve message design and enhance decision-making is far-reaching. We expect our innovative methods will have wide application for designing risk communication aids for those with low literacy, an important strategy for eliminating disparities in disaster response and subsequent health effects. PUBLIC HEALTH RELEVANCE: This research will provide an opportunity to develop a more accurate projection of how the public, especially those with low literacy, might react to a radiological terror event or other high-risk messaging. Having measures of emotional and physiological response will be important for interpreting the linkages between the cognitive positionings/perceptions and the behavioral intentions related to the final actions taken by the public should an event actually occur. This research will specifically contribute to national preparedness in the case of a terror event, but also advance the science of developing interdisciplinary models that improve decision making under uncertainty using innovative methods such as perceptual mapping and physiological testing.